Furnace for roasting ores.



Patented Nov. 25, 1902.

T. EDWARDS.

FURNACE FOB-BOASTING DBES.

(Application filed Sept. 28. 1901.)

3 Shuts-Sheet l.

.- UNITED STATEsj PATENT OFFICE.

THOMAS EDWARDS, OF SEBASTOPOL, BALLARAT, VICTORIA, AUSTRALIA.

FURNACE- FOR ROASTING ORES.

SPEGIFIGATION forming part of Ibetters Patent No. 714,464, dated November 5, 1902- Application filed September 28, 1901- Serial No. 76,868. (No model.)

f To all whom it may concern:

Be it known that I, THOMAS EDWARDS, a subject of the King of Great Britain, and a resident of sebastopol, Ballarat, State of Victoria, Australia, have invented certain new and useful Improvements in Furnaces for the Roasting of Ores and for other Purposes, of

which the following is a specification.

My invention is an improvement upon that form of reverberatory furnace for roasting ores disclosed by me in Letters Patent of the United States, dated April'9, 1895,No.537,024.

Inmy present invention I have sought to improve the structure of the furnace, to provide a water-cooled rabble which will resist the destructive action of the heat and gases, to give tothe rabbles nearest the fire-box or discharge end of the furnace a more rapid rotation in respect to those at the feed end of the furnace, and generally I have sought to increase the durability of the furnace as well 1 as its efficiency. i

In the drawings, Figure 1 is a plan view of apart of the furnace. partly broken away. Fig. 3 is a transverse sectional view of the furnace. Fig. 4=is a detail sectional view of one of the rabbles. Fig. l 5 is a crosssectional view of the foot of the rabble, showing the manner of attaching thereto removable wear blocks or teeth; and Fig. 6 is a side view of the rabble; Fig. 7, a detail View.

From the drawings it will be seen that the furnace is substantially of the same elongated form as that shown in my patent referred to,

being pivoted centrally of its length at 1, so

that it may be tilted by any suitable mechan-' ism-such, for instance, as that shown in Fig.

2 and consisting of a screw 2, pivotally conthrough a nut 4, fixed to a suitable part of the stationary frame or foundation, and thus tilt the furnace-frame. l

The furnace comprises the side girders 5,

of angle-iron, having straight upper edges and 1 lower edgeslinclinin-g upwardly from the pivat suitable intervals to make a strong structure. The girders when the furnace is made of considerable length are formed in sections-- Fig. 2 is a side view,

thus forming the side walls of the furnacechamber, and the furnace-chamber is completed by the arch 11 and the end walls.

The furnace is provided at one end with the fire-box 12, as in the patent referred to, and adjacent to this is located the discharge 13 for the roasted ores, while at the other end" of the furnace is arranged the outlet-flue 14.

This line, it will be seen from Fig. 2, is not in the plane of the longitudinal plane of the furnace, but is elevated in respecttlhereto, consisting of a bent pipe or shell located at the upper part of the furnace-chamber and opening into the same in a downward direction. By this arrangement of the dischargeflue for the gases and products of combustion I avoid the disadvantage present in other arrangements- 5. e., the blowing of a portion of the ore by the strong draft from its proper position in the furnace into the main flue which connects with thedischarge-flue. This blowing out of parts of the ore is especially apt to occur when the rotary rabble is in operation, stirring and turning over the ore and in a measure raising it.

My present furnace chamber, like that shown in my patent referred to, is provided with lateral doors 14' for feeding air or for gaining a sight of the interior, and air-holes 15 are also provided at the fire-box end of the furnace. I employ rabbles in my present invention for stirring the ore and for giving it a traversing movement along the hearth from the feeding to the discharge end. These rabbles 16 in their general arrangement and operation are like those described in said patent, with the exceptions to be now noted. I provide means whereby the rabbles will be protected from the destructive action of the heat and of the gases evolved in the roasting of the ore. For this purpose the foot por I tions 17 of those rabbles it is desired to protions.

tect are made hollow. These hollow foot portions are connected with the stems or shafts 18 of the rabbles, which are also hollow and extend up through the arch of the furnace and are connected with suitable driving mechanism outside the furnace-chamber for giving the rabbles their stirring or rotary movement. Each hollow stem 18 is made in sect-ions, which are flanged at 19 and are secured together by bolts. A pipe 20, flanged at its upper end, is held within the lower stem-section by the flange of the pipe being clamped between the flanges of the stem-sec- This pipe communicates with the interior of the upper stem-section. It has about it an annular space in the lower section for the passage of water, and at its lower end it connects with a pipe 21, which extends horizontally of the foot portion and opens into the same, there being a space about this pipe also for the passage of the water. From a point near the upper end of the lower section a discharge-pipe 22 extends, its mouth being directed toward a discharge-pan 23, extending about the stem and supported in fixed position in the arch of the furnace, from which pan the cooling-water is led away, as will be hereinafter described.

In Fig. 2 I show water-supply connections leading to the stems of several of the rabbles, these being nearest the fire-box and of course exposed to the most intense heat.

Any desired number of rabbles may be cooled. The supply-pipe for the Water is indicated at 24, extending in a direction longitudinally of the furnace and having branches 25 extending upwardly and discharging into the upper open ends of the stems, suitable valves 26 being provided to regulate the flow. The water after passing through the pipes 20 21 flows through the space about said pipes within the hollow rabble and within the lower section of the stem, thus effectually cooling the same and preventing their destruction by the heat and gases and from the upper ends section 30, which conveys the water to any suitable point. By this arrangement the furnace may be tilted as desired without interfering with the cooling action, and the rabbles may likewise be rotated freely while the cooling-water is acting thereon.

In furnaces where only a low degree of heat is required the water will circulate freely through the hollow of the rabble and the interior pipes can be dispensed with;

For placing the pipe 21 in position the foot of the rabble is provided with an opening 31. This is closed by a plug 32.

In order to increase the life of the rabble, I provide the same with removable wearingblocks 33. For the attachment of these blocks the foot of the rabble is formed with lateral flanges 34, and the wearing-blocks are provided with fingers or extensions 35, engaging these flanges, by which they are held in place thereon. The Wearing-blocks in being placed on or removed from the foot portions are simply moved longitudinally of the flanges. The rabbles are driven by bevel-gears on their stem meshing with similar gears on a lineshaft For supporting the driving connections I employ an upper framework supported on the side girders 5. This framework comprises the angle-iron frames 36, extending transversely at intervals above the arch of the furnace, said frames being bolted to the upper angle irons 37 of the side girders. These transverse frames are of general triangular form, comprising inclined sides 37' and upper and lowercross-pieces 38. These crosspieces support angle-iron beams 39, which extend longitudinally of the furnace, and to them are bolted the bearings 40 of the rabble spindles or stems. At the apex of these triangular supporting-frames bearings 41 are supported, in which the line -shaft turns. The angle-iron framework surmounting the furnace is further provided with braces 41. The line-shaft is driven from a pulley 43 on a short transverse shaft 44, having its bearings 45 supported on the angle-iron frame. This shaft carries a bevel-gear 46, meshing with a gear on a shaft 47, which is geared to the line-shaft through the gearing 48.

I find it desirable to increase the stirring action as the ore reaches a higher degree of roasting upon its approach to the fire-box end of the hearth, and for this purpose I give a greater speed to the rabbles located nearest the fire-box. For instance, I so proportion the gearing of the rabble at the position A that it makes two revolutions for each revolution of the rabble located at B, while the rabble located at 0-4. e., the nearest to the fire-boxis geared up to make fourrevolutions to one of that of the rabble at B. By this ar= rangement the ore is progressively subjected to a higher temperature. It is stirred and turned over in the hot air. Thus the sulfates are more quickly reduced to oxids, while at the feeding end it is desirable to have the ore particles remain in one position for a iomewhat longer period to be acted on by the eat.

The stems of the rabbles pass through iron frames 49 into the furnace, said frames being arranged in the arch or roof-of the furnace.

The side girders, it will be noticed, are formed of vertical plates having angle-irons riveted thereto at their upper and lower edges.

The ore may be supplied to the machine in any suitable mannerfor instance, through an opening at Y.

I claim as my invention-- 1. In combination in an ore-roasting furnace, a rabble having a hollow stem and foot, said stem being formed in sections, a waterconducting pipe held in place within the lower section by being clamped between the two sections, a discharge-pipe leading from the lower section and an inlet-pipe leading to the upper section, substantially as described.

2. In combination with a tilting ore-roasting furnace, a hollow rabble therein having a 1 hollow stem, means for rotating the hollow stem and rabble and a water supply and discharge pipe connected with the hollow stem,

, said water supply and discharge pipe being arranged to permit the furnace to be tilted,

substantially as described.

p 3. In combination with an ore-roastin g f urnace, a plurality of rabbles with means for driving .them simultaneously at different speeds, substantially as described.

4. In combination with an ore-roasting furnace having a fire-box at one end and a discharge at the other end, a plurality of rabbles disposed-at dilferent points along the furnace and means for driving the same, the rabbles nearest the fire-box being driven at a greater the shafting and the rabble-stems, and said transverse frame being located above the f urnace and supported by the angle-iron girders thereof, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

THOMAS EDWARDS.

Witnesses:

HENRY E. OooPER, F. L. MIDDLETON. 

